A magnetic tape cassette in which a single reel with magnetic tape wound thereon is rotatably housed in a flat cassette case having a generally square flat form, and a disk cassette in which a disk is rotatably housed in a flat cassette case having a generally square flat form, have recently been used to back up data stored on memory for computers.
These cassettes vary in form, depending on manufacturers. However, a wide variety of cassettes with similar outside dimensions are manufactured to provide for interchangeability between library units of different manufacturers. There are cases where cassettes of different types are archived or used together. For example, an LTO cassette and a DLT cassette are used in approximately the same applications. The LTO cassette and the DLT cassette are approximately the same in width, but the LTO cassette is smaller in inserting-direction length and height than the DLT cassette.
These cassettes are usually housed in their dedicated cassette storing cases when not being used, such as when being conveyed, when being archived, etc. In addition, the cassette is provided with a recording member, such as a bar code label, a memory chip, etc., for identifying the recorded contents. The cassette is housed in the cassette storing case in a fixed direction so that the recording member, such as a bar code, etc., can be read out even in the housed state.
Furthermore, the cassette and the cassette storing case are generally provided with a structure for regulating positional shift when stacked, in order to enable transfer, transportation, and conveyance when stacked. For instance, the cassette is provided on the bottom surface with protrusions and the cassette storing case is provided on the top surface with recesses. When they are stacked, the protrusions are fitted into the recesses to regulate positional shift between them.
Hence, most of the cassettes are similar in longitudinal and transverse dimensions, and it is troublesome to identify the longitudinal and transverse lengths of a cassette and house the cassette into a housing case in a fixed direction. Because of this, there is a problem that housing of a cassette in an incorrect direction will disable reading of the aforementioned recording member.
To prevent housing of a cassette in an incorrect direction, it is possible to provide protrusions, such as reverse-insertion preventing ribs, etc., in a cassette storing case so that when inserted in an incorrect direction, the cassette is projected by the protrusions and thus the lid of the housing case is not closed. However, there will be a fear of a cassette being damaged, if the user closes the lid forcibly without being aware of an error in the housing direction. Furthermore, if cassettes of different kinds, slightly different in outside dimensions but similar in form, are used together, it will become difficult to identify a dedicated cassette storing case corresponding to each cassette. Thus, there will also be a fear that (1) a cassette will be housed in an incorrect housing case, (2) a cassette or a housing case will be damaged, and (3) archiving will be confused.
The present invention has been made in view of the points mentioned above. Accordingly, it is a first object of the present invention to provide a cassette storing case which is capable of preventing a cassette from being housed in an incorrect direction and easily identifying a dedicated cassette storing case corresponding to a cassette, while assuring the function of preventing positional shift that would be caused during stacking.
In cases where different cassette storing cases are manufactured for housing two kinds of magnetic tape cassettes (also called magnetic tape cartridges), identifying the correspondence between a cassette and a cassette storing case to house each cassette into a dedicated housing case is troublesome and reduces operability.
That is, in the case where the same user frequently uses two kinds of cassettes at the same place and archives them in the same library unit, the fear of damage to the cassette and the housing case and confusion in archiving will arise if the cassette is forcibly housed in an incorrect housing case.
Hence, it is preferable to house two kinds of cassettes in the same cassette storing case. In this case, the housing case is formed into a dimension that can house the larger cassette. For this reason, if the smaller cassette is housed in the housing case, there will arise a fear that (1) the smaller cassette will tend to move easily, (2) the cassette and the housing case will rub against each other because of vibration during conveyance, and (3) etching will occur. Thus, it is necessary to house the smaller cassette so that it is not moved within the housing case. In addition, it is desirable to prevent the cassette from being housed in the cassette storing case in an incorrect direction and desirable not to disable reading of the aforementioned recording member. Furthermore, it is necessary that the existing cassettes be housed without changing the form of the cassettes solely for the purpose of housing the cassettes in the aforementioned cassette storing case.
The present invention has been made in view of the points mentioned above. Accordingly, it is a second object of the present invention to provide a cassette storing case which is capable of housing two kinds of cassettes without moving them in the interior.